public static class ObjectUtils.Null extends Object implements Serializable
Class used as a null placeholder where null has another
meaning.
For example, in a HashMap the
HashMap.get(java.lang.Object) method returns
null if the Map contains null
or if there is no matching key. The Null placeholder can
be used to distinguish between these two cases.
Another example is Hashtable, where null
cannot be stored.
Copyright © 2003–2016 The Apache Software Foundation. All rights reserved.